Hans Peter Haselsteiner, a major shareholder in Strabag SE (WBAG:STR) acquired 15% minority stake in SIGNA Holding GmbH on December 7, 2021. Hans Peter Haselsteiner, a major shareholder in Strabag SE (WBAG:STR) completed the acquisition of 15% minority stake in SIGNA Holding GmbH on December 7, 2021.